A US woman who shot and killed her husband and two adult children before taking her own life is thought to have committed the shocking crime as a result of being ostracised from the religion she was raised in.

A federal judge sentenced a former Arkansas judge Wednesday to five years in prison — a stiffer punishment than prosecutors recommended — after he admitted giving young male defendants lighter sentences in return for personal benefits that included sexual favours.

Every time I tell a mate I’m doing a story on cryptocurrency, they invariably ask me the same two questions: should they invest their own hard-earned money, and which cryptocurrency will get them a Lamborghini/yacht/island quickest?

In a 60 Minutes online exclusive, reporter Liz Hayes quizzed Australian Prime Minister Malcolm Turnbull on his relationship with the unpredictable Twitter aficionado and US president Donald Trump ahead of their meeting at the White House Friday.

Union seeks uniform journalist shield laws

Australia needs a consistent set of shield laws to protect journalists with confidential sources amid an unprecedented assault on press freedom, a media union says.

With at least five journalists across the country currently fighting court orders to reveal their sources or face contempt of court convictions, the Media, Entertainment & Arts Alliance (MEAA) wants the Standing Council on Law and Justice representing attorneys-general across all jurisdictions to create uniform shield laws.

While some states have introduced such laws, many are riddled with inconsistencies and loopholes, and only a uniform approach will give journalists the protection they need to tell stories the public need to hear, MEAA director of media Paul Murphy said.

"Today we face the unprecedented situation where five journalists are facing the possibility of criminal proceedings, of convictions, fines and possible imprisonment for doing nothing other than doing their job in the public interest," Mr Murphy told reporters on Tuesday.

Four of the reporters - Steve Pennells, Adele Ferguson, Richard Baker and Nick McKenzie - attended the MEAA's call for action in Melbourne.

Ms Ferguson, who's fighting a WA Supreme Court order to reveal sources for an unauthorised biography about billionaire Gina Rinehart, said current laws meant she faced "every journalist's most-feared nightmare".

Hundreds of journalists have signed an online petition supporting Ms Ferguson and saying orders to reveal sources go against long-established principles of journalism.